Lecture 18 - vaccines

Question 1

Question: What is active immunization, and how does it work?

Answer 1

Answer: Active immunization involves exposing the immune system to a weakened, killed, or part of a pathogen, stimulating a protective response and creating memory cells for long-term protection.

Question 2

Question: What is passive immunization, and when is it used?

Answer 2

Answer: Passive immunization involves the transfer of pre-formed antibodies to provide immediate protection. It is used for short-term immunity, such as for newborns or individuals exposed to toxins like snake venom.

Question 3

Question: How does active immunization differ from passive immunization?

Answer 3

Answer: Active immunization induces the body’s immune response, creating long-term memory, whereas passive immunization provides immediate protection via antibodies but does not induce memory.

Question 4

Question: How do killed inactivated vaccines work, and what are their advantages?

Answer 4

Answer: Killed inactivated vaccines contain pathogens that are dead and unable to replicate. They are safe, stable, and acceptable for immunocompromised individuals but may require multiple doses and adjuvants.

Question 5

Question: What are live attenuated vaccines, and what are their advantages?

Answer 5

Answer: Live attenuated vaccines contain weakened live pathogens that replicate in the body to produce a strong immune response. They often provide long-term immunity with fewer doses but should not be used in immunocompromised individuals.

Question 6

Question: What are subunit vaccines, and why are they considered safe?

Answer 6

Answer: Subunit vaccines contain only the parts of the pathogen (antigens) necessary to stimulate an immune response, reducing the risk of side effects and making them safe for immunocompromised individuals.

Question 7

Question: Why was the smallpox eradication campaign successful?

Answer 7

Answer: It succeeded because of an effective vaccine providing lifelong immunity, no animal reservoir, no subclinical infections or carriers, only one Variola serotype, and strong government commitments.

Question 8

Question: What are the key criteria for a useful active vaccine?

Answer 8

Answer: A useful vaccine should be safe, effective, provide long-lasting immunity, be cheap, stable, and easily administered.

Question 9

Question: What are live attenuated vaccines and how do they work?

Answer 9

Answer: Live attenuated vaccines contain weakened pathogens that replicate in the host, producing a strong and long-lasting immune response, mimicking natural infection.

Question 10

Question: What are the advantages of live attenuated vaccines?

Answer 10

Answer: They elicit a strong, authentic immune response, provide long-term protection, usually require only a single dose, and don’t need adjuvants.

Question 11

Question: What are the disadvantages of live attenuated vaccines?

Answer 11

Answer: There is a risk of reversion to virulence, potential complications in immunocompromised individuals, and they require careful storage.

Question 12

Question: What are subunit vaccines and why are they safe?

Answer 12

Answer: Subunit vaccines contain only specific antigens or parts of the pathogen, offering a very safe option for immunization, especially in immunocompromised individuals.

Question 13

Question: What are toxoid vaccines and how do they work?

Answer 13

Answer: Toxoid vaccines contain inactivated toxins (toxins treated with formaldehyde) that stimulate the production of antibodies to neutralize the toxin, preventing disease.

Question 14

Question: What are adjuvants and what role do they play in vaccines?

Answer 14

Answer: Adjuvants are substances added to vaccines to boost the immune response by promoting better antigen presentation, T-cell differentiation, and longer-lasting immunity.

Question 15

Question: What are killed inactivated vaccines?

Answer 15

Answer: Killed inactivated vaccines contain microorganisms that have been killed by heat or chemicals, preventing them from replicating, making them safe for all populations.